The present invention relates generally to a piston and a connecting rod assembly for an internal combustion engine and, more particularly, to a piston and a connecting rod assembly which is readily assembled and provides improved oil lubrication and cooling.
An improved piston and connecting rod assembly is disclosed in U.S. Pat. No. 5,115,725. Contrary to conventional construction systems using a piston pin, the assembly disclosed in that patent provides a center of rod oscillation for a connecting rod with connecting rod considerably closer to the piston crown surface. Consequently, if lengths of an arm of a crank shaft and a connecting rod are lengthened by that amount, the cylinder displacement increases without changing dimensions and output of the engine is increased.
In the above mentioned piston and connecting rod assembly, a cavity formed by a piston skirt receives successively a slide member, a receiving end of a connecting rod, an annular collar for supporting the receiving end, an arresting sleeve for arresting the annular collar, and a retaining tube. Assembly problems can be caused by improper orientation of the individual pieces. In particular, since clearance between the retaining tube and the annular collar is small, an inadvertent inclination of the annular collar will prevent smooth rotation as the retaining tube is threadedly fitted into the piston skirt. Also, since a sliding portion of the receiving end is lubricated with oil previously supplied to a cooling oil chamber in the piston, the sliding portion can be insufficiently lubricated.